Mathematical instrument



APPLICATION FILED JAN. 3, I920.

Patented June 13, 1922.

2 SHEETS-SHEET 1.

Kerr: 0)? L.Ma iison V. L. MATTSON.

MATHEMATICAL INSTRUMENT.

APPLICATION FILED JAN. 3, 1920.

VERNON L. MATTSON, OF SOUTH CHARLESTON, WEST VIRGINIA.

MATHEMATICAL INSTRUMENT.

Specification of Letters Patent. Patented J 13 192 Application filedJanuary 3, 1920. Serial No. 349,272.

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Be it known that I, VERNON L. MATTSON, a citizen of the United States,residing at South Charleston, in the county of Kanawha and State of WestVirginia, have invented new and useful Improvements in MathematicalInstruments, of which the following is a specification.

This invention relates to mathematical instruments mainly designed forsurveyors and the principal object of the invention is to provide meansfor computing the sine and cosine of an angle when the degree of theangle and the length of the hypotenuse is known.

WVhile the invention is more particularly designed for use by surveyorsit will of course be understood that the device may be used in othersituations and for other purposes.

This invention also consists in certain other features of constructionand in the combination and arran ement of the several parts, to behereinafter fully described, illustrated in the accompanying drawlngsand specifically pointed out in the appended claims.

In describing my invention in detail, reference will be had to theaccompanying drawings wherein like characters denote like orcorresponding parts throughout the several views, and in which 2- Figure1 is a plan view with parts broken away.

Figure 2 is a section on line 2-2 of Figure 1. v

Figure 3 is a detail view of the stationary and movable arms.

Figure 4 is a section on line 1-4 of Figure 5.

Figure 5 is a section on line 5-5 of Figure 4. a

Figure 6 is a diagrammatic view.

As shown in these views 1 indicates a casing which is preferably of theshape shown in Figure 1, which shows the casing as having one sideformed in an arc of acircle. This edge may be provided with the scale 2which is divided into degrees, minutes and seconds. This casing isprovided with a cover 3 which extends over part of the Gas ing. Thiscover rotatably supports the crank shaft 4: which carries the gear wheel5. The cover, upon its inner face is-proto each other as shown.

vided with the tubular boss 6 which receives the shaft 7 to which issecured the upper disc 8 and the small gear 9, said gear meshing withthe gear 5. The spring 10, located in the boss, tends to force the shaftand its disc downwardly. A similar boss 11 is formed on the bottom ofthe casing and a stationary shaft 12 is supported within said boss. Alower disc 13 is provided with a tubular hub 14: which surrounds theshaft 12 and 1s mounted within the boss 11. A- spnng 15 in said bosstends to force the disc and its hub upwardly. As will be seen the upperand lower discs have their centers out of allgnment, though said discsoverlap, as shown. The discs are provided with teeth 16 on theircircumference and the discs are geared together by the toothed wheels 17located on the stub shaft 18 which is suitably supported in the casing.In this way when the crank shaft is turned both discs will be rotated.

A stationary arm 19 has its inner end supported on the shaft 12 and itsother end resting on the curved edge of the casing. The inner end ofthis arm is provided with a socket 20 and this socket is engaged by therounded end of a movable arm 21 which isplvoted to the upper end of theshaft 12 wlthin said socket. The outer end of this movable arm extendsover the curved edge of the case and is provided with the Vernier 22which cooperated with the scale 2. A

cross arm 23 is pivotally connected at 24 to the stationary arm 19 andthis cross arm is slotted as at 25 to receive the arm 21. A T-shapedhead 26 is slidably mounted on the arm 21 and on the arm 23, said arms21 and 23 passing through the head at right angles The head is providedwith openings for receiving said arms so that both arms are embraced bythe head. The head carries friction rollers 27 for engaging the arms.The arm 21 has upper and lower notches on its front face forming thetongue 28, said notches receiving the rollers on the front face of thehead. As will be seen the arms are located between the discs.

The head is provided with upper and to said shaft so that it may slidethereon and a shaft 32 passes through the other bracket and the wheel ofthis bracket is keyed to this shaft. These shafts 31 and 32 extend atrightangles to each other and the wheels are arranged at rightangles toeach other. The upper shaft 31 is connected with the counter mechanism33 while the lower shaft is connected with the counter mechanism 34. Theupper shaft and its counter mechanism is carried by the cross arm 23while the lower shaft and its counter mechanism is carried by themovable arm 21. The outer end of the cross arm is slidably mounted on apart of the cover. The edge of the tongue 28 forms a straight edge whichis in the same plane as the circumferential center of the wheel 30. Bothcounter mechanisms are so arranged that they will indicate eachrevolution of the wheels 30 and as will be seen these wheels are engagedby the upper and lower discs which are frictionally held in engagementwith said wheels by the springs 10 and 15. Thus as the discs are rotatedthe wheels will revolve, causing the shafts to rotate and thus actuatethe counter mechanisms. As the T-shaped head is moved the wheels willslide upon theshafts.

Counter mechanism 35 is located on the outer end of the stationary armand the shaft 36 of this mechanism has its inner end journaled in abracket 37 located on said arm under the upper disc 8. A wheel 38 issecured to this shaft and engages the underface of said upper disc.

Supposing a surveyor has run a line 220 feet with its extremity 30 dueeast. He will then have an angle such as A, B, C in Figure 6 of 30, thehypotenuse of which is 220 feet in length. He has to then find out thelength of A, C and C, B. In computing the length of these lines on myinstrument the surveyor would first move the movable arm 21 to the 30mark-on the scale. Then he would rotate the crank 4 until the numbers220 appeared in the counter This movement of the upper and lower discswould cause the wheels 30 to actuate their counters to indicate thelength of lines A C and C B, the counter 34 giving the cosine of theangle multiplied by the length of the hypotenuse 220 and counter 33 thesine of the angle multiplied by 220.

As the arm 21 is moved the arm 23 and the head 26 will also be moved,the head sliding on arm 21 and also on arm'23, this movement will movethe wheels 30 upon their shafts and relatively to the centers ofthediscs so that said wheels will be rotated more Or less by themovement of said discs according to their positions on the discs.

I may provide suitable means for pressing the discs apart and out ofcontact with the wheels when the arms are to be moved. As shown suchmeans consists of a handle 40 connected with the shaft 7 and passingthrough the cover so that said shaft and its disc may be raised and alever 41 pivoted in the side of the casing and engaging the lower discso that said lower disc may be lowered.

As before stated my instrument is mainly designed for surveyors but itwill of course be understood that it may be used for securing the cosineand sine multiplied by one side of the triangle where the degree of theangle and length of one side is known, or any side of a right trianglewhere one side and either angle is known.

Attention is called to the fact that the pivotal point of the cross armis in alignment with the center of the upper disc.

What I claim is 1. An instrument of the class described comprising apair of spaced rotatable elements, means for rotating said elements inunison, setting means actuated by one element by having a part engagingthe inner face thereof, said means indicating the length of the knownside of a right triangle,

a pair of counter mechanisms actuated by said rotary elements forindicating the lengths of the other sides of the triangle. saidmechanisms having portions located between the elements and engaging theinner faces thereof and setting means for the said mechanisms movable tocorrespond with the degree of the angle.

2. An instrument of the class described comprising a pair of spacedrotary elements, manually actuated means for rotating said elements inunison, indicating means actuated by one of the elements for'indicatiugwhen said elements have been moved to a position correspondent to theknown length of one side of a right triangle, a pair of countermechanisms for indicating the lengths of the other sides, means foractuating said mechanisms by the movement of the elements, said meansincluding parts located between the elements and engaging the innerfaces thereof and means for adjusting the actuating means relative tothe elements in accordance with the degree of the angle known.

3. An instrument of the class described comprising a pair of spacedrotary elements, manually actuated means for rotating said elements inunison, indicating means actuated by one of the elements for indicatingwhen said elements have been moved to a degree correspondent to theknown length of one side of a right triangle, a pair of countermechanisms for indicating the lengths of the other sides, means foractuating said mechanisms by the movement of the elements, said meansincluding parts arranged between the elements and engaging the innerfaces thereof and means for adjusting the actuating means relative tothe elements in accord ance with the degree of the angle, such meanscomprising movable arms to which the actuating means are attached, astationary scale and a marker on one of the movable arms for cooperatingwith the scale.

4. An instrument of the class described comprising a casing, a pair ofdiscs rotatably supported in said casing, said discs having theircenters out of alignment, manually actuated means for rotating saiddiscs in unison, a stationary arm extending between the discs, amanually movable arm pivotally connected to the end of the stationaryarm, a head slidably mounted on said movab e arm, a cross arm having oneend pivot-ally connected with the stationary arm and extend ing at anangle therefrom and slidably connected with the head for causing saidcross arm'to be moved with the manuallyv op.- erated arm, upper andlower wheels carried by said head and enga ing the upper and lower discsso as to be rotated thereby, counter mechanism connected with eachwheel, a scale and marker associated with the movable arm forfacilitating the proper adjustments of the wheels on the head relativeto the dlscs, a setting counter mechanism and means for actuating thesame by the upper disc, said setting counter mechanism indicating whenthe discs have beenmoved sufiiciently to rotate the wheels to causetheir counter devices to give the desired results.

5. An instrument of the class described comprising a casing, upper andlower discs rotatably supported therein and having their centers out ofalignment, means for rotating said pair of discs in unison, a stationaryarm extending between the discs, a movable armhaving one end pivotallyconnected with the stationary arm, a head slidably mounted on saidmovable arm, a cross arm having one end pivotally connected to thestationary .arm and slidably connected with the head, upper and lowerWheels carried by said head and engaging with the discs so as to berotated by the movement of said discs,

counter mechanisms each having a shaft slidably engaging the wheels,said shafts actuating the counter mechanisms when the wheels arerotated, at setting counter mechanism actuated by the upper disc forindicating when the discs have been moved to a position to solve theproblem and a scale and marker associated with the movable arm forindicating when said arm has been moved to properly adjust the wheels onthe head in relation to the discs.

In testimony whereof I aifix my signature.

VERNON L. MATTSO'N.

